Films based on polyamide and on polymers containing polyamide blocks and polyether blocks

Abstract

The invention relates to films based on PA-6 or PA-6,6 and on a copolymer containing polyamide (6 or 6,6) blocks and ploytetramethylene glycol blocks. They have greater impact strengths than PA-6 or PA-6, 6 film.

We claim: 
     
       1. A film based on (i) a polyamide consisting essentially of polyamide-6 or polyamide-6,6 and (ii) a polymer containing polyamide blocks and polyether blocks, and having a structure of a polyamide matrix in which nodules of the polymer (ii) are dispersed, wherein the nodules of the polymer (ii) are smaller than 0.3 μm; the polyamide blocks consisting essentially of polyamide-6 or polyamide-6,6 and the polyether blocks consisting essentially of polytetramethylene; and the ratio of the polyamide/polyether in the polymer (ii) is in the range of from 50/50 to 95/5. 
     
     
       2. The film according to claim 1, wherein the impact strength according to ISO 7765-1 (Method B) is higher than that of a film based on polyamide consisting essentially of polyamide-6, or polyamide-6,6. 
     
     
       3. The film according to claim 1, wherein the transparency is at least equal to that of a film based on polyamide consisting essentially of polyamide-6, or polyamide-6,6. 
     
     
       4. The film according to claim 1, wherein the ratio of polyamide/polyether in the polymer (ii) is in the range of between 60/40 and 75/25. 
     
     
       5. The film according to claim 2, wherein the ratio of the polyamide/polyether in the polymer (ii) is in the range of between 60/40 and 75/25. 
     
     
       6. The film according to claim 1, wherein the polyamide in (i) is the same as in the polyamide blocks of (ii). 
     
     
       7. The film according to claim 1, wherein the nodules of the polymer (ii) are about 0.1 μm.